A) Field of Invention
The present invention relates to an electronic device for processing information, and more particularly to an electronic device for processing information which contains a removable card.
B) Description of Related Art
Electronic devices for processing information are currently available which perform a variety of functions. FIG. 1 shows a conventional device 10 which can, for example, perform the function of either a dictionary, encyclopedia or bible. A rear surface 11 of the device 10, as shown in FIG. 2, includes a recess 12 which supports a removable card. The function performed by the device 10 depends on the type of removable card inserted into the recess 12. Specifically, should a user desire the device 10 to function as a dictionary, then a removable card containing dictionary-related information is inserted into the recess 12. Alternatively, should a user desire the device 10 to function as an encyclopedia, then a removable card containing information relating to an encyclopedia is inserted into the recess 12.
FIG. 3 shows an exploded view of a conventional removable card 20. The conventional removable card 20 generally includes five components: (i) a first plate 21, (ii) a first case 22, (iii) a printed circuit board 23, (iv) a second case 24, and (v) a second plate 25.
The first plate 21 is made of polyvinyl chloride or metal and is attached to the first case 22 by an adhesive. An outer surface of the first plate 21, although not shown in FIG. 3, generally includes a logo or other marketing information.
The first case 22 is a plastic material which includes recesses 26. The first case 22 also includes hinges 27 and guides 28. The hinges 27 are positioned to project from a front surface of the first case 22 where the guides 28 project from side surfaces. Additionally, a resilient U-shaped device 29 is attached to the first case 22. The U-shaped device 29 includes a first side 30 which is attached to a back surface of the first case 22, and a second side 31 which defines a channel 32.
The printed circuit board 23 contains electronic components 33 on both its upper and lower surfaces. Also provided on the printed circuit board 23 are gold pads 34 and gold contacts contacts 35. The printed circuit board 23 is positioned above the first case 22. As a result, when the removable card 20 is assembled, components 33 located on the lower surface of the printed circuit board 23 are fit into the recesses 26 provided on the first case 22.
The second case 24 is positioned above the printed circuit board 23 and contains recesses 36. Thus, components 33 located on the upper surface of the printed circuit board 23 are fit into the recesses 36. Also, during assembly, the first case 22 and second case 24 are ultrasonically welded together to secure the printed circuit board 23.
A second plate 25 is attached to the second case 24 with an adhesive to complete the assembly of the removable card 20. The second plate 25 is typically made of stainless steel.
Referring again to FIG. 2, the recess 12 contains a number of components which interface with the removable card 20. Specifically, the recess 12 includes pins 13 which provide a DC power supply. The pins 13 are positioned such that they contact the gold pads 34 on the printed circuit board 23 when the removable card 20 is inserted into the recess 12.
A conducting strip 14 is also provided in the recess 12. The conducting strip 14 connects the gold contacts 35 on the printed circuit board 23 with contacts inside the device 10 which are not shown. The conducting strip 14 is an elastomeric connector which uses a silver impregnation to achieve a low initial resistance of 0.1 ohms.
Hinge slots 15 are also included in the recess 12 to receive the hinges 27 provided on first case 22 of the removable card 20. Similarly, guide slots 16 are provided in the recess 12 to receive the guides 28. A prong 17 overlaps the recess 12 and engages the channel 32 provided on the U-shaped device 30 when removable card 20 is inserted into the recess 12.
The above-described removable card 20 does, however, have certain drawbacks. In particular, the removable card 20 contains a large number of parts which increase the cost of the removable card 20 and, additionally, make the removable card 20 difficult and expensive to manufacture. Also, by having an excess number of parts, the removable card 20 undesirably adds to the weight of the device 10.